Oleispira antarctica gen. nov., sp. nov., a novel hydrocarbonoclastic marine bacterium isolated from Antarctic coastal sea water

Abstract

Oleispira antarctica gen. nov., sp. nov., a novel hydrocarbonoclastic marine bacterium isolated from Antarctic coastal sea water The taxonomic characteristics of two bacterial strains, RB-8 T and RB-9, isolated from hydrocarbondegrading enrichment cultures obtained from Antarctic coastal marine environments (Rod Bay, Ross Sea), were determined. These bacteria were psychrophilic, aerobic and Gram-negative with polar flagella. Growth was not observed in the absence of NaCl, occurred only at concentrations of Na + above 20 mM and was optimal at an NaCl concentration of 3-5 % (w/v). The major cellular fatty acids were monounsaturated straight-chain fatty acids. The strains were able to synthesize the polyunsaturated fatty acid eicosapentaenoic acid (20 : 5v3) at low temperatures. The DNA G+C contents were 41-42 mol%. The strains formed a distinct phyletic line within the c-Proteobacteria, with less than 89?6 % sequence identity to their closest relatives within the Bacteria with validly published names. Both isolates exhibited a restricted substrate profile, with a preference for aliphatic hydrocarbons, that is typical of marine hydrocarbonoclastic micro-organisms such as Alcanivorax, Marinobacter and Oleiphilus. On the basis of ecophysiological properties, G+C content, 16S rRNA gene sequences and fatty acid composition, a novel genus and species within the c-Proteobacteria are proposed, Oleispira antarctica gen. nov., sp. nov.; strain RB-8 T (=DSM 14852 T =LMG 21398 T ) is the type strain. INTRODUCTIONHydrocarbon-degrading micro-organisms usually exist in very low abundance in the absence of oil pollution. A pollution event is rapidly followed by a bloom of these micro-organisms, the populations of which expand to nearly complete dominance of the viable microbial community during the period of contamination (Margesin & Schinner, 1999;Harayama et al., 1999). The properties of hydrocarbon compounds depend on the ambient temperature. Short-chain alkanes become less volatile and more water-soluble at low temperatures, whereas longer-chain compounds precipitate under cold conditions as waxes, respectively rendering them bioavailable and inaccessible to microbes. Such behaviour at low temperatures obviously reflects the establishment of specific oil-based marine microbial communities at these temperatures that are somehow different from those observed in a temperate climate. The most important permanently cold habitat is the ocean, since the temperature of more than 90 % of the seawater volume is below 5 uC. Genera that are typically well represented in cold, petroleum-contaminated sites are Acinetobacter, Arthrobacter, Mycobacterium, Pseudomonas, Rhodococcus and Sphingomonas, many of which can grow solely on hydrocarbon compounds and have been previously characterized as petroleum degraders of terrestrial origin (Rosenberg et al., 1992;MacCormack & Fraile, 1997). Although the role of these microbes is evident in the petroleum-degradation process in cold marine environments, Abbreviations: PLFA, phospholipid fatty acid; ...

High bicarbonate assimilation in the dark by Arctic bacteria

“…A psychrophilic strain of this group (Oleispira antarctica) does not take up common carbohydrates and amino acids as sole C sources, and shows a preference for aliphatic hydrocarbons (Yakimov et al, 2003). This metabolic preference could explain the low leucine uptake for this group seen in the autoradiograms.…”

Obligate oil-degrading marine bacteria

“…and Roseobacter spp., when spiked with crude oil, Alcanivorax spp., when spiked with the branched aliphatic hydrocarbon pristine, and Cycloclasticus spp., when spiked with PAHs [34]). A complementary study to analyze the effects of temperature and added nutrients revealed that Alcanivorax only appeared when nutrients were added, and that organisms affiliated to the genus Oleispira (first isolated as a cold-adapted OHCB from crude-oil enrichments of Antarctic seawater [15], bloomed in microcosms maintained at 4°C [59]. Oleispira was also shown to be present in oil-degrading microbial communities in other microcosm studies performed at low temperatures.…”

“…The three other genera of the OHCB group, despite being represented by numerous members, are monophyletic and represented by the three type species Oleiphilus messinensis [14], Oleispira antarctica [15] and Thalassolituus oleivorans [16].…”

Marine Oil-Degrading Microorganisms and Biodegradation Process of Petroleum Hydrocarbon in Marine Environments: A Review

“…[35] Naphthalene, anthracene, phenanthrene, and pyrene Aeram onas punctata TII [14,53] Phenanthrene and Chrysene Vibrio, Pseudoalteromonas, Marinomonas [31] n-Alkanes aromatic hydrocarbon, naphthalene, phenanthrene and anthracene Cycloclasticus oligotrophus [23,73] n-Alkanes, branched alkanes and alkylbenzenes Alcanivorax sp. [22,29,30,48,75] Aliphatic hydrocarbons, alkanoles, and alkanoates Oleiphilusand, Oleispira [28,74] Alkanes…”